Blackboard-trestle with adjustable map-displayer and roll-support.



No. 815,974. I 'PATENTED MAR. 27.1906.

M. NACKEN. v

BLAGKBOARD TRBSTLBWITH ADJUSTABLE MAP-'DISPLAYER AND ROLLSUPPORT.

I 2 SHEETSfSHEIET l.

Ziz ven faz' as al1/n' QPWMXW" No. 815,974. PATENTED MAR. 27, l1906..

M. NAGKEN. r

BLAGKBOARD TRBSTLE WITH ADJUSTABLE MAP DISPLAYER l AND ROLL SUPPORT.

APPLIUATION FILED APRJS. 1905. 2 SHEBTSHBBT 2- 3 A l A37 wc'zzesses v Zn/vena?? m- A @mimi-mm.

UNITED sTATEs PATENT oEEioE.

MATHIAs NAcKEN, E wEsELEN, NEAR AIX-LA-CHAPELLE, GERMANY.

BLACKBOAR-TRESTLE WITH ADJUSTALE MAP-DISPLAYER AND ROLL-SUPPORT.v

Specification of Letters Patent.

Patented March 2'?, 1906.

Application med Aprilisfleo. Serin No. 256.316.

dom of Prussia, Empire of Germany, lhalveinvented certainv new and useful Improve-` ments in Blackboard-Trestles with Adjustable Map-Displayers and Roll-Supports; and Ido hereby declare the. following to be a full, -clear, and exact description ofthe invention, such as will enable others skilled inthe art "to which it appertains to make and'useV the Same.' My present invention relates to blackboard-trestles; and the object in view is to provide a blackboard-trestle with adjustable means ca able of displaying mapsV of various sizes an in the maps when not displayed.' i

y means of this improvement not only an eXtra trestle for the display of maps but also an'especialshelf for the accommodation of Vthe maps when not in actual Ause arejsuper'- luous, and besides'this much valuable space is saved thereby. ,j

In the accompanying drawings, Figure 1 is a front elevationVV of a blackboard-trestle pro- Fig. 21s ai o? Fig. 1.

vided with. my improvements. sectional view taken on linej2 2` Fig. 3 is a sectional view' taken Online 3 3 of Fig. l. Figs. 4, 5, and 6.are showing details of construction on a larger scale. Y j Fig1`7v is a iront elevation of another blackboard-trestle, "showing a modification of my improvements.

Fig. 8 is a sectional viewtaken on line 8 8 of Fig. 7. Figs. 9 and 10 areshowing details of construction on a larger scale.,

,Y The illustrated blackboard-trestles are in bothcases consisting of side posts 1, united by the cross-bars 2, 3, and 4, and of a trarne `5, hinged tothe rear of said side posts. VIn 'order to allow ofthe blackboard-trestlebeing 'set at ,different slants, ,two lock-bars 6 are hinged to the cross-bar 3 and provided with indentions V7 of such shape that when the lock-bars are pressed into the notches 8 ofthe cross-bar of frame 5 the trestle issecurely held in the desired 1position. Trestles for largeror double blac boardsare'preferably provided lwith casters'9, as indicated in Figs. 7 and 8. Between thecr'oss-bars 3 and 4 a' box 10 is removably held, containing the lockable compartments 11 and 12 for thereception of letters for reading-machines and other small-'articles used ina4 school-room,

lof the side posts 1. j 'for the reception ofthe pintles. 19V of a blackalso with means for supportp and two' open receptacles 13 and 14, of which the upper one' is destined for the handy reception of chalk, whereas the lower one is containing a tin boX 15 for the reception of Sponges.

In Fig. 1 the inner faces of the side posts 1 are armed with plates 16, having vrojections 17 and downwardly-arranged s ots corresponding with' slots 18, opening in the front The slots 18 are serving board, which may be easily replaced by a counting-machine or by a reading-machine by removing the thumb-screw 20 passing through a-slotted disk 21, secured to the blackboard 22, and screwed into one of the projections 17.

AS shown in Figs. 7 and' 8, the blackboard 22 of Figs. l and 2 is here replaced by a reading-machine 23 and a counting-machine 24, connected by cords, chains, or the like 25, running over disks 26. The inner faces of the side posts 1 are lfor this purpose provided with longitudinal grooves 27 and 28, in which slide-blocks 29v and l30 are held and to which said! cords A 25 are secured'. The slots 18, arranged in Fig. 1' directly in the face of the side posts 1, are here arran ed in the slideblocks 29 and 30, intowhi'c the pintles of 4the reading-'machine and of the countingmachine are inserted through the slots 31.

(See Fig. 8.) In all other respectsth'ese machines may be secured in any desirable posivtion Vto the slide-blocks 29 and 30, as the blackboard 22 to the side posts 1` of Figs. 1 and 2; but as these machines are movably held artificial friction must be employed to hold them securely in any desirable position. To this end the projections 17 of two of these slide-blocks are perforated forv the reception ofthe outer end of pins`32, arranged within a recess 33 in the slide-block 29 at the left-hand sideand in a' similar recess inthe slide-block `30 a't the' right-hand side' of the trestle. Normally the 'outer end of each' of said pins isprojecting over the faceV kof the proj ection 17 4; but when the thumblscrew 20 'is screwed home the inner end of, the' pin 32 will be pressed against the bottom of the groove, and thus` press; the outer face of the slide-block containing said pin against the plates '34 and angle-irons 35j, retaining said slide-block in the groove guiding it.l As soon as the thumbscrew 20 is unscrewed the sprin 36 will retract the pin 32, so that the sliV be freely moved againl IOO e-block can p partly in theface of the side post 1. In these guide-slots rectangular slide-bars 38 are arranged, whose free ends are united by a tubular cross-head 39. To fix these bars 38 at different heights, their lower ends are of cylindrical shape for the reception of the eyes of handles 40, which may be inserted into any of the notches 41, arranged at different heights in the outer corners of the side-post faces. Below the cross-head 39 a rod 42 is arranged, upon which hooks 43 are placed for the reception of maps, having but a cord secured to their upper pole, or for the sus ension of pictures, drawings, or the like. T ese hooks are shown on a larger scale in Fig. 4, where plainly may be seen how these hooks are prevented from rotating by their upper lugs 43 when said hooks are carrying a map or the like. The cross-head 39 is provided with a rectangular bore 44 running through from end to end, in which correspondinglyshaped draw-bars 45 may be inserted. ToY

the outer end of each of these draw-bars is secured a cross-bar 46 in such a manner as to form arms of unequal lengths, of which each is provided with a hook-forming notch 47 for the reception of a pintle of the upper mappole. On the cylindrical middle part of the cross-head 39 an auxiliary arm 48 1s arranged in such a manner as to be swung out of the way when maps of a greater width than the length of the cross-head are to be displayed, whereas maps of the same or of a lesser width than the length of said cross-head can be displayed with the aid of one of said draw-bars and the auxiliary arm 48. From the above it will be seen that all the diHerent parts carried by the slide-bars 38 are forming the mapdisplayer proper.

v When the trestle is very high, so that it is impossible to conveniently reach the top thereof, the cross-head 39 must be differently connected with the slide-bars 38 as when the trestle is'low. To this end the narrow part of the slots 37 opening in the face of the side posts 1 must run through to the top of the latter to let the brackets 49 pass, which are secured to the slide-bars 38 and b which the tubular cross-head 39 is firmly he d. (See Figs. 7 and 8.) As in this arrangement of the cross-head the rod 42 cannot be secured between the slide-bars 38, as shown in Figs. 1

and 2, it is attached directly to the lower side of the cross-head.

To provide a convenient storage-place for the maps not in actual use', brackets or supports 50 are secured to the rear of the trestle, either to the upper cross-bar 2, as shown in Fig. 2, or to the side posts 1, as indicated in Fig. 8. For convenient shipment of these tlestles the supports 50 are made foldable toward each other, but cannot be swung outwardly on account of the noses 51. Besides being used for the reception of rolled-up maps these supports may also be employed for supporting rolls of drawing-paper and the like.

If, for instance, a long and wide map is to be displayed, the draw-bars 45 are drawn out until the pintles of the upper inap-pole can be placed in the notches 47 of the cross-bars 46, whereupon-the slide-bars 38 are raised to the right height after the Shanks of the handles 40 have been turned at right angles to the faces of the side posts. The handles bcing brought opposite the desired notches 41 are turned outward into said notches, thus securing the map-displayer with the map held thereby at the desired height. If the map has to hang vertically and this end cannot be attained by the shorter arms of the cross-bars 46 the longer arms must be turned to the front and the map attached thereto, and if this does not suhce the lock-bars 6 must be readjusted to give the whole trestle a steeper slant.

If maps of equal or lesser width than the length of the cross-head are to be displayed, one of the pintles of the upper map-pole is placed in the notch of one of the cross-bars 46, whereas the other pintle is placed in thc corresponding notch of the auxiliary arm 48 after beinor moved to the right position on the cross-head 39. To make the auxiliary arm 48 just as well do when the longer arms of the cross-bars 46 are employed as when their shorter arms are in use, it is provided with the notches 52 and 53, of which the notch 52 corresponds with the notch of the longer arm and the notch 53 with the notch of the shorter arm of any one of said cross-bars 46.

I claim- 1. A blackboard trestle, comprisin T in combination braced side posts, longitudinal guide-slots therein, a map-displayer, slidears of said map-displayer movably held in said guide-slots, means for securing the mapdisplayer to the side posts at diiiierent heights, a cross-head uniting the free ends of said slide-bars, draw-bars held by said cross-head and provided with hooked arms, an auxiliary hooked arm loosely mounted on said crosshead, a rod beneath said cross-head to sustain said auxiliary arm in two different positions, hooks slidingly arranged upon said rod, extensions on said hooks pressing against said cross-head to prevent said hooks from rotating, and foldable roll-supports secured to the rear of the trestle for supporting rolledup maps.

2. In a blackboard-trestle of the kind described, in combination, braced side posts, T- shaped guide-slots therein opening in the face of said side posts, a map-displayer, slide-bars of said map-displayer movably arranged in said guide-slots, a tubular cross-head uniting IOO the free ends of said slide-bars, rotary handles on the lower ends of .said slide-bars for securing the ma -dis layer to the side posts at different heiglts, dIiaW-bars of rectan ular cross-section held by said tubular crossead and provided With supporting-arms of unequal lengths, an auxiliary arm rotatorily and slidingly mounted on said tubular crosshead, a rod beneath said cross-head to sustain said auxiliary arm in its Working position and to keep it out of the Way When the cross-bars of both draw-bars are simultaneously employed, hooks slidingly arranged on MATHIAS NACKEN.

v Witnesses HENRY QUADJLIEG, GERARD OELLERs. 

